CA1225951A - Lithographic printing plates - Google Patents
Lithographic printing platesInfo
- Publication number
- CA1225951A CA1225951A CA000458513A CA458513A CA1225951A CA 1225951 A CA1225951 A CA 1225951A CA 000458513 A CA000458513 A CA 000458513A CA 458513 A CA458513 A CA 458513A CA 1225951 A CA1225951 A CA 1225951A
- Authority
- CA
- Canada
- Prior art keywords
- composition
- compound
- mls
- treatment
- lithographic printing
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
- G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
- G03F7/004—Photosensitive materials
- G03F7/06—Silver salts
- G03F7/063—Additives or means to improve the lithographic properties; Processing solutions characterised by such additives; Treatment after development or transfer, e.g. finishing, washing; Correction or deletion fluids
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Photosensitive Polymer And Photoresist Processing (AREA)
- Printing Plates And Materials Therefor (AREA)
- Manufacture Or Reproduction Of Printing Formes (AREA)
- Developing Agents For Electrophotography (AREA)
- Photoreceptors In Electrophotography (AREA)
- Compounds Of Unknown Constitution (AREA)
- Electromagnets (AREA)
- Paper (AREA)
- Dry Formation Of Fiberboard And The Like (AREA)
- Air Bags (AREA)
- Printing Methods (AREA)
- Laminated Bodies (AREA)
- Graft Or Block Polymers (AREA)
Abstract
IMPROVEMENTS IN OR RELATING TO LITHOGRAPHIC
PRINTING PLATES
Abstract A lithographic printing plate having metallic silver image areas is treated with a proteolytic enzyme and an oleophilising compound to improve ink receptivity.
PRINTING PLATES
Abstract A lithographic printing plate having metallic silver image areas is treated with a proteolytic enzyme and an oleophilising compound to improve ink receptivity.
Description
2~5951 _ This invention relateb to lithographic printing plates.
As is well known a lithographic printing plate has ink-receptive (oleophilic) image areas and water-receptive (hydrophilic) non-image areas lying in substantially the same plane.
The type of lithographic printing plate to which this invention relates is that in which the image areas are formed from metallic silver. Such plates may be produced by the diffusion transfer process or the physical development process.
In the diffusion transfer process, a silver halide emulsion layer is image-wise exposed to form a latent negative image which is developed in contact with a receiving layer containing development nuclei so that a ~ positive metallic silver image is formed. Two systems ; are known, i.e. the two sheet system in which the silver halide layer and the receiving layer are on separate substrates and the silver halide diffuses from the negative layer to the positive layer when the two are ; ~ ~placed~in contact in the presence of a developer and the single-sheet system where both the negative silver halide layer and the positive receiving layer are coated onto the same substrate.
In the physical development process, a silver halide emulsion layer is image-wise exposed to form latent image nuclei upon which silver is deposited to form the metallic silver image.
The substrate used for the single sheet diffusion 30 transfer process, the physical development process and the receiving layer of the two-sheet diffusion transfer process forms the non-image areas of the final printing plate. Thus the substrate may be suitably treated paper or plastics material, or a metal such as aluminium which 35 may be grained and anodised to render its surface more lithographically suitable.
The resultant plate needs to be treated with an . ` ~
S~35~L
oleophilising compound to increase the oleophilic properties of the silver image areas. Various treatments are known and are detailed in payes 105 and 106 of "Photographic Silver Halide Diffusion Processes" by Andre Rott and Edith Weyde (The Focal Press).
Evan after such treatment, however, it has been found that if gelatin has been used as the binder in the silver-halide emulsion, the surface of the image areas is reluctant to take ink.
It is an o~ject of the present invention to improve the ink receptivity of lithographic printing plates having image areas of metallic silver derived from silver halide emulsions.
In accordance with the present invention, this is achieved by applying to the plate a proteolytic enzyme and subsequently or simultaneously applying an oleophilising compound.
Accordingly one aspect of the present invention provides a finishing composition for treating a lithographic printing plate having image areas of metallic silver, the composition comprising (i) a proteolytic enzyme and (ii) a compound capable of rendering the silver image areas oleophilic.
The finishing composltion will generally be an essentially aqueous solution containing~effective amounts of the enzyme and the oleophilising compound. Typically, the enzyme constitutes from 0.1% to I0.0% by weight of the total composition and the oleophilising compound constitutes from 0.05% to 5.0% by weight of the total composition.
The enzyme is chosen from that class of enzymes which specifically catalyse the breakdown of proteins. For example, trypsin, pepsin, ficin, papain or bacterial proteinases such as "Gelatase C" (T.M.) (ABM Chemicals Ltd) may be used although trypsin and papain are preferred. Enzyme activity is very pH dependent and enzymes in general will not withstand extremes of pH or temperature .
~I~XS951 or the presence of strong oxidising or reducing agents. Hence the composition should be formulated and used in a manner such that these are avoided.
Mercapto compounds and cationic surfactants such as quaternary ammonium compounds are preferred oleophilising compounds.
In accordance with a preferred embodiment, a desensitising treatment for the non-image areas is carried out either simultaneously or su~sequently. In the former case, the finishing composition additionally comprises an effective amount of a lithographic desensitising compound.
Typically, the desensitising compound constitutes from about 1.0% to 10.0%
by weight of the total composition.
Carbohydrates such as gum ara~ic and dextrin may be used as desensitising compounds without affecting the enzyme.
The run-length of the treated plates may ~e increased by applying a lacquer (based, for example on phenol or cresol novolak resins) to the image areas. It is believed that treatment of the plate with the finishing composition in accordance with the invention provides better adhesion of the lacquer to the image areas and thus a longer run-length.
The following Examples illustrate the invention.
~e~
Single Sheet DTR System Electrochemically grained and anodised aluminum substrates were coated,in order, with a nucleation layer comprising silver sol. in gelatin binder and asilver chlorobromide-gelatin emulsion. These coated substrates were then exposed and developed in a diffusion transfer type developer to form lithographic printing plates. The Z259Sl -5~
composition of the developer was as follows:-Sodium Sulphite 509 hydroquinone 129 Phenidone 39 sodium hydroxide 109 sodium thiosulphate 59 Water to 1 litre Phenidone is a proprietary form of 1 -phenyl-3-pyrazolidone.
The plates were then washed with water to remove the chemically developed silver and the silver image areas remaining on the plates were subjected to the treatments detailed below. In all cases the plates were buff-dried after the treatment and then put on a FAG Offset Press 104, which is~ a proo~ing press, and the ink-receptivity determined from the number of ~impressions required before good quality prints were obtained.
In general, the ink-rsceptivity was considered to be very good if less than 5 ~impressions were~required, good if from 5 to 10 impressions were required, moderate if from ~10~ to 15~impressions were required and poor iF from l5 to 20 impressions~were required. I f greater than 20 impressions did not yield a aatisfactory prlnt, the image was considered~to have no oleophilicity for practical purposes. ~ ~
In each case the treatment solution was applied to a plate at an amount of 50 mls/2m for 20 seconds at room temperatur~e.
Treatment 1 -The ~followin g solution was used: ~
~:
37 mls water 1.25 gms TritonX-100 (T.M.) (non-ionic surfactant) 7.3 mls Gum Ara~ic 0.25 mls ortho phosphoric acid 0.6 mls Proxel XL-2 (T.M.) (bactericide) ~5 mls of a 2% solution of 2-mercapto~enzthiazole -~"in polyethylene glycol 200 (PEG 200).
:, ; . .
~ ,, : , , . , ~
;25~351 (Triton X-100 is a proprietory form of octyl phenoxy polyethoxy ethanol).
Treatment 2 The following buffered trypsin solution was used 54.77 gms Borax 200 mls 0.lM hydrochloric acid 10 gms Trypsin tbovine pancreatic) 150 mls Gum Arabic 0.5 gm Calcium nitrate deionised water to l litre pH 8.0 Treatment 3 This treatment was identical to Treatment 2 except that the excess solution was wiped-off and the plate was then treated as in Treatment l.
Treatment 4 The:solution of Treatment 2 was used to which had been added 100mls of a 2% solution of 2-mercapto benzthiazole in polyethylene glycol 200.
Treatment 5 ; 20 The following solution was used:
: 500 mls water 10 gms ~ sodium dihydrogen phosphate : 150 mls Gum Arabic 100 mls . 2% solution of phenylmercaptotetrazole in polyethylene glycol 200 : l.ON sodium hydroxide to give pH 6.0 Treatment 6 The solution of Treatment 2 was used to which had been added 100 mls of a 2% solution of phenylmercaptotetrazole in PEG 200.
Treatment 7 The following buffered solution of Ficin was used:
500 mls water 4.77 gms Borax 200 mls 0.lM hydrochloric acid ., _ .
595~
150 mls Gum Arabic 100 mls 2~ phenylmercaptotetrazole in PEG 200 10 gms Ficin Water to 1 litre pH 8.0 Treatment 8 The following solution of Pepsin was used:
500 mls water 10 gms Pepsin 150 mls Gum Arabic 100 mls 2% phenylmercaptotetrazole in PEG 200 Orthophosphoric acid to pH 2.0 Water to 1 litre Treatment 9 The following solution of papain was used:
500 mls water 10 gms sodium dihydrogen phosphate ; ~ ~l.ON sodium hydroxide to pH 6.0 10 gms ~ papain ~ ~ 100 mls ~2% phenylmercaptotetrazole in PEG 200 20~ ~ Water~to l litre :, Treatment 10 A~s~olution was used which was similar to the solution~of Treatment 9 but containing l gm/litre papain Treatment;~
~ ~ The solution of Treatment 2 was used to which had been added 10gms/litre cetyltrimethylammonium bromide Treatment~12 ~ The solution of Treatment 2 was used to which had been added 10 gms/litre cetylpyridinium chloride.
Treatment I3 The~solution of Treatment 2 was used to which had been added lgm/litre trypsin.
Treatment~ 14 ; ~ The solution of Treatment 2 was used to which had been added 0.lgm/litre trypsin.
Treatment 15 ~: . : :
.
.
t~;:z~igsl The following solution o~ a bacterial enzyme was used:
800 mls water 10 yms potassium hydrogen phthalate l.ON sodium hydroxide to pH 6.0 10 mls Proteinase 200L
10gms cetylpyridinium chloride water to l litre Proteinase 200L is bacterial neutral proteinase : 10 obtained from ABM Chemicals.
The followlng results were obtained. / .
~15 /
/
: . /
:
/
/
:~ /
:
/
./
:~L22595i.
g H
H
E~ a c~ a c:
~ O ~ O E~ O O E~
C~ O E~ O E~ O O E~
C~
W E3 ~ a ~
:~ z z o o z o ~ ~ ~ a a; ~: ~ o o Z O O O O O O ~ O W O E~ ~ O O O
H Z Z 1~ ~ Z
Z ~I ~ ~ O O O O O O ~
D O O O N N N N N N r~ O O O O
O N N N ~ C ~_1 ~1 ~1 ~1 O ~ S S S
o s ~ s ~1)a) ~ a~ a) o ~
N N N O O O O O O r-l t~ C C C ~) ~ ~) ~J ~) ~ ~ ~1 .-1 ~1 ~1 z a) q) (I~ 4 ~ S ~: ~ C C
H Q Q R n1 U~ O O O ~) ~ C) O C) C) ~ r H ~ ~) ~ h ~ ~ h H id ni ~ e ~
o ~ C
~3 z ~ ~ o ~ I o ~ 1 1 ~ s s s s s ~
O ~ Z ~ Q C ) C,) C~ c) ~ ,~ Ul z ~ :~ ~ ~ o ~ ~ ~ ~ ~ ~ o z z ~l ~ o o O dP dP dQ Od~ oP O
z ~l ~l ~ z ~ ~ ~ ~ o ~ - l o o ~ ~
E~
z E~ ~ ~ ~ ~ D 1` 0 ~ O ~ ~`3 ~ ~ n ~;
E~
i ` - ~IL~2S951 Example 2 Two sheet DTR System This system comprised an electrochemically grained aluminium substrate coated with a silver sol. of average 5~ particle diameter 50A and a paper base coated with a silver chlorobromide-gelatin emulsion.
The paper was exposed and the assembly processed in the conventional manner in an ADT 026 processing machine (Develop GmbH) using the developer of Example l.
After the sheets were peeled apart the silver image remaining on the aluminium receptor sheet was treated with fixing solution prior to testing the resultant lithographic printing plate on the proof press.
~ Mottle blinding is often associated with plates produced in this way. The extent of it depends on several factors including, in particular, the amount of gelatin or other binder, in the donor sheet and the ~degree to which it has been hardened.
A plate showing this effect when treated in the conventional~manner was treated as in treatment 6 of Example l. This treatment removed the blinding and resulted in a pIate with excellent ink receptivity over the~whole of the silver image.
- Example 3 ;25 ~ An~ electrochemically grained and anodised aluminium sheet was coated with a silver iodobromide-gelatin emulsion to about 0.1 gm Ag m 2 This was exposed and developed for 20 seconds in a physical developer containing lO gm/litre silver nitrate and an Fe /Fe redox couple to produce a lithographic printing plate having a metallic silver image of about 5 gm Ag~m . This plate when treated as in treatment 6 showed much better ink receptivity than one treated with an oleophilising solution not containing the enzyme.
Example 4 The following finishing composition was prepared:
:; ~
, .
2S9S~
37 mls Trypsin/borate buffer solution 1.25 mls Triton X-lO0 7.3 mls Gum Arabic 0.6 mls Proxel XL2 ( bactericide) 2.5 mls 2% solution of 2-mercaptobenzo thiazole in polyethylene glycol The pH of the composition was 7.8. The buffer solution had the following ingredients:
50 mls 0.025N sorax.
20 mls O.lN Hydrochloric acid.
0.5 g Trypsin 20 mg Calcium nitrate.
30 mls water.
A similar finishing composition was prepared except that the trypsin was omitted from the buffer solution.
A single-sheet diffusion transfer plate consisting of an electrolytically grained and anodised aluminium substrate coated with a positive receiving layer ~20 ~ consistlng of silver particles in a gelatin binder and a silver chlorobromide/gelatin emulsion, was exposed and deveLoped~in the manner of Example l.
The resultant lithographic printing plate was washed with~water, and~ the two finishing compositions were~applied respectively to separate areas thereof. The plate was rubbed with normal lithographic inking-in ink.
The area treated with the enzyme-containing finishing composition accepted the ink immediately whereas considerable rubbing was necessary before the other area reluctantly accepted the ink.
ExamPle 5 Example 4 was repeated except that papain was the enzyme used and the composition had a pH of 6.
Similar results were obtained.
~ .
.
Example 6 Examples 4 and 5 were repeated except that phenylmercaptotetrazole was used as the oleophilising compound. Similar results were obtained.
Example 7 The folIowing finishing composition was prepared:
75 mls Trypsin/borate buffer.
5 g Triton X405 (non-ionic surfactant).
1 g Cetyltrimethylammonium brornide.
15 mls Gum Arabic.
The pH was adjusted to 8.0 with lN sodium hydroxide.
An equivaIent composition without the trypsin was also prepared and the two finishing compositions were applied to separate areas of a developed lithographic printin~g plate produced as in Example 4. Results similar to those of Example 4 were obtained.
ExamPle 8 ~ Exam? les 4 to 7 were repeated using a lithographic printing~p~late produced by the two-sheet diffusion transfer system. Similar results were again obtained.
~ The two-sheet system consisted of an electrolytically grained aluminium substrate coated with a;~silver particle/gelatin positive receiving layer and a paper~substrate coated with a silver halide/gelatin emulsion.;
Example 9 The finishing compositions of Examples 4 to 7 were appl-ied to lithographic printing plates produced by a physical development process and similar results were obtained.
The plates used consisted of an electrolytically grained aluminium substrate coated with a silver halide/gelatin emulsion. After exposure, the plates were placed in a physical developer containing a silver salt and a reducing agent.
As is well known a lithographic printing plate has ink-receptive (oleophilic) image areas and water-receptive (hydrophilic) non-image areas lying in substantially the same plane.
The type of lithographic printing plate to which this invention relates is that in which the image areas are formed from metallic silver. Such plates may be produced by the diffusion transfer process or the physical development process.
In the diffusion transfer process, a silver halide emulsion layer is image-wise exposed to form a latent negative image which is developed in contact with a receiving layer containing development nuclei so that a ~ positive metallic silver image is formed. Two systems ; are known, i.e. the two sheet system in which the silver halide layer and the receiving layer are on separate substrates and the silver halide diffuses from the negative layer to the positive layer when the two are ; ~ ~placed~in contact in the presence of a developer and the single-sheet system where both the negative silver halide layer and the positive receiving layer are coated onto the same substrate.
In the physical development process, a silver halide emulsion layer is image-wise exposed to form latent image nuclei upon which silver is deposited to form the metallic silver image.
The substrate used for the single sheet diffusion 30 transfer process, the physical development process and the receiving layer of the two-sheet diffusion transfer process forms the non-image areas of the final printing plate. Thus the substrate may be suitably treated paper or plastics material, or a metal such as aluminium which 35 may be grained and anodised to render its surface more lithographically suitable.
The resultant plate needs to be treated with an . ` ~
S~35~L
oleophilising compound to increase the oleophilic properties of the silver image areas. Various treatments are known and are detailed in payes 105 and 106 of "Photographic Silver Halide Diffusion Processes" by Andre Rott and Edith Weyde (The Focal Press).
Evan after such treatment, however, it has been found that if gelatin has been used as the binder in the silver-halide emulsion, the surface of the image areas is reluctant to take ink.
It is an o~ject of the present invention to improve the ink receptivity of lithographic printing plates having image areas of metallic silver derived from silver halide emulsions.
In accordance with the present invention, this is achieved by applying to the plate a proteolytic enzyme and subsequently or simultaneously applying an oleophilising compound.
Accordingly one aspect of the present invention provides a finishing composition for treating a lithographic printing plate having image areas of metallic silver, the composition comprising (i) a proteolytic enzyme and (ii) a compound capable of rendering the silver image areas oleophilic.
The finishing composltion will generally be an essentially aqueous solution containing~effective amounts of the enzyme and the oleophilising compound. Typically, the enzyme constitutes from 0.1% to I0.0% by weight of the total composition and the oleophilising compound constitutes from 0.05% to 5.0% by weight of the total composition.
The enzyme is chosen from that class of enzymes which specifically catalyse the breakdown of proteins. For example, trypsin, pepsin, ficin, papain or bacterial proteinases such as "Gelatase C" (T.M.) (ABM Chemicals Ltd) may be used although trypsin and papain are preferred. Enzyme activity is very pH dependent and enzymes in general will not withstand extremes of pH or temperature .
~I~XS951 or the presence of strong oxidising or reducing agents. Hence the composition should be formulated and used in a manner such that these are avoided.
Mercapto compounds and cationic surfactants such as quaternary ammonium compounds are preferred oleophilising compounds.
In accordance with a preferred embodiment, a desensitising treatment for the non-image areas is carried out either simultaneously or su~sequently. In the former case, the finishing composition additionally comprises an effective amount of a lithographic desensitising compound.
Typically, the desensitising compound constitutes from about 1.0% to 10.0%
by weight of the total composition.
Carbohydrates such as gum ara~ic and dextrin may be used as desensitising compounds without affecting the enzyme.
The run-length of the treated plates may ~e increased by applying a lacquer (based, for example on phenol or cresol novolak resins) to the image areas. It is believed that treatment of the plate with the finishing composition in accordance with the invention provides better adhesion of the lacquer to the image areas and thus a longer run-length.
The following Examples illustrate the invention.
~e~
Single Sheet DTR System Electrochemically grained and anodised aluminum substrates were coated,in order, with a nucleation layer comprising silver sol. in gelatin binder and asilver chlorobromide-gelatin emulsion. These coated substrates were then exposed and developed in a diffusion transfer type developer to form lithographic printing plates. The Z259Sl -5~
composition of the developer was as follows:-Sodium Sulphite 509 hydroquinone 129 Phenidone 39 sodium hydroxide 109 sodium thiosulphate 59 Water to 1 litre Phenidone is a proprietary form of 1 -phenyl-3-pyrazolidone.
The plates were then washed with water to remove the chemically developed silver and the silver image areas remaining on the plates were subjected to the treatments detailed below. In all cases the plates were buff-dried after the treatment and then put on a FAG Offset Press 104, which is~ a proo~ing press, and the ink-receptivity determined from the number of ~impressions required before good quality prints were obtained.
In general, the ink-rsceptivity was considered to be very good if less than 5 ~impressions were~required, good if from 5 to 10 impressions were required, moderate if from ~10~ to 15~impressions were required and poor iF from l5 to 20 impressions~were required. I f greater than 20 impressions did not yield a aatisfactory prlnt, the image was considered~to have no oleophilicity for practical purposes. ~ ~
In each case the treatment solution was applied to a plate at an amount of 50 mls/2m for 20 seconds at room temperatur~e.
Treatment 1 -The ~followin g solution was used: ~
~:
37 mls water 1.25 gms TritonX-100 (T.M.) (non-ionic surfactant) 7.3 mls Gum Ara~ic 0.25 mls ortho phosphoric acid 0.6 mls Proxel XL-2 (T.M.) (bactericide) ~5 mls of a 2% solution of 2-mercapto~enzthiazole -~"in polyethylene glycol 200 (PEG 200).
:, ; . .
~ ,, : , , . , ~
;25~351 (Triton X-100 is a proprietory form of octyl phenoxy polyethoxy ethanol).
Treatment 2 The following buffered trypsin solution was used 54.77 gms Borax 200 mls 0.lM hydrochloric acid 10 gms Trypsin tbovine pancreatic) 150 mls Gum Arabic 0.5 gm Calcium nitrate deionised water to l litre pH 8.0 Treatment 3 This treatment was identical to Treatment 2 except that the excess solution was wiped-off and the plate was then treated as in Treatment l.
Treatment 4 The:solution of Treatment 2 was used to which had been added 100mls of a 2% solution of 2-mercapto benzthiazole in polyethylene glycol 200.
Treatment 5 ; 20 The following solution was used:
: 500 mls water 10 gms ~ sodium dihydrogen phosphate : 150 mls Gum Arabic 100 mls . 2% solution of phenylmercaptotetrazole in polyethylene glycol 200 : l.ON sodium hydroxide to give pH 6.0 Treatment 6 The solution of Treatment 2 was used to which had been added 100 mls of a 2% solution of phenylmercaptotetrazole in PEG 200.
Treatment 7 The following buffered solution of Ficin was used:
500 mls water 4.77 gms Borax 200 mls 0.lM hydrochloric acid ., _ .
595~
150 mls Gum Arabic 100 mls 2~ phenylmercaptotetrazole in PEG 200 10 gms Ficin Water to 1 litre pH 8.0 Treatment 8 The following solution of Pepsin was used:
500 mls water 10 gms Pepsin 150 mls Gum Arabic 100 mls 2% phenylmercaptotetrazole in PEG 200 Orthophosphoric acid to pH 2.0 Water to 1 litre Treatment 9 The following solution of papain was used:
500 mls water 10 gms sodium dihydrogen phosphate ; ~ ~l.ON sodium hydroxide to pH 6.0 10 gms ~ papain ~ ~ 100 mls ~2% phenylmercaptotetrazole in PEG 200 20~ ~ Water~to l litre :, Treatment 10 A~s~olution was used which was similar to the solution~of Treatment 9 but containing l gm/litre papain Treatment;~
~ ~ The solution of Treatment 2 was used to which had been added 10gms/litre cetyltrimethylammonium bromide Treatment~12 ~ The solution of Treatment 2 was used to which had been added 10 gms/litre cetylpyridinium chloride.
Treatment I3 The~solution of Treatment 2 was used to which had been added lgm/litre trypsin.
Treatment~ 14 ; ~ The solution of Treatment 2 was used to which had been added 0.lgm/litre trypsin.
Treatment 15 ~: . : :
.
.
t~;:z~igsl The following solution o~ a bacterial enzyme was used:
800 mls water 10 yms potassium hydrogen phthalate l.ON sodium hydroxide to pH 6.0 10 mls Proteinase 200L
10gms cetylpyridinium chloride water to l litre Proteinase 200L is bacterial neutral proteinase : 10 obtained from ABM Chemicals.
The followlng results were obtained. / .
~15 /
/
: . /
:
/
/
:~ /
:
/
./
:~L22595i.
g H
H
E~ a c~ a c:
~ O ~ O E~ O O E~
C~ O E~ O E~ O O E~
C~
W E3 ~ a ~
:~ z z o o z o ~ ~ ~ a a; ~: ~ o o Z O O O O O O ~ O W O E~ ~ O O O
H Z Z 1~ ~ Z
Z ~I ~ ~ O O O O O O ~
D O O O N N N N N N r~ O O O O
O N N N ~ C ~_1 ~1 ~1 ~1 O ~ S S S
o s ~ s ~1)a) ~ a~ a) o ~
N N N O O O O O O r-l t~ C C C ~) ~ ~) ~J ~) ~ ~ ~1 .-1 ~1 ~1 z a) q) (I~ 4 ~ S ~: ~ C C
H Q Q R n1 U~ O O O ~) ~ C) O C) C) ~ r H ~ ~) ~ h ~ ~ h H id ni ~ e ~
o ~ C
~3 z ~ ~ o ~ I o ~ 1 1 ~ s s s s s ~
O ~ Z ~ Q C ) C,) C~ c) ~ ,~ Ul z ~ :~ ~ ~ o ~ ~ ~ ~ ~ ~ o z z ~l ~ o o O dP dP dQ Od~ oP O
z ~l ~l ~ z ~ ~ ~ ~ o ~ - l o o ~ ~
E~
z E~ ~ ~ ~ ~ D 1` 0 ~ O ~ ~`3 ~ ~ n ~;
E~
i ` - ~IL~2S951 Example 2 Two sheet DTR System This system comprised an electrochemically grained aluminium substrate coated with a silver sol. of average 5~ particle diameter 50A and a paper base coated with a silver chlorobromide-gelatin emulsion.
The paper was exposed and the assembly processed in the conventional manner in an ADT 026 processing machine (Develop GmbH) using the developer of Example l.
After the sheets were peeled apart the silver image remaining on the aluminium receptor sheet was treated with fixing solution prior to testing the resultant lithographic printing plate on the proof press.
~ Mottle blinding is often associated with plates produced in this way. The extent of it depends on several factors including, in particular, the amount of gelatin or other binder, in the donor sheet and the ~degree to which it has been hardened.
A plate showing this effect when treated in the conventional~manner was treated as in treatment 6 of Example l. This treatment removed the blinding and resulted in a pIate with excellent ink receptivity over the~whole of the silver image.
- Example 3 ;25 ~ An~ electrochemically grained and anodised aluminium sheet was coated with a silver iodobromide-gelatin emulsion to about 0.1 gm Ag m 2 This was exposed and developed for 20 seconds in a physical developer containing lO gm/litre silver nitrate and an Fe /Fe redox couple to produce a lithographic printing plate having a metallic silver image of about 5 gm Ag~m . This plate when treated as in treatment 6 showed much better ink receptivity than one treated with an oleophilising solution not containing the enzyme.
Example 4 The following finishing composition was prepared:
:; ~
, .
2S9S~
37 mls Trypsin/borate buffer solution 1.25 mls Triton X-lO0 7.3 mls Gum Arabic 0.6 mls Proxel XL2 ( bactericide) 2.5 mls 2% solution of 2-mercaptobenzo thiazole in polyethylene glycol The pH of the composition was 7.8. The buffer solution had the following ingredients:
50 mls 0.025N sorax.
20 mls O.lN Hydrochloric acid.
0.5 g Trypsin 20 mg Calcium nitrate.
30 mls water.
A similar finishing composition was prepared except that the trypsin was omitted from the buffer solution.
A single-sheet diffusion transfer plate consisting of an electrolytically grained and anodised aluminium substrate coated with a positive receiving layer ~20 ~ consistlng of silver particles in a gelatin binder and a silver chlorobromide/gelatin emulsion, was exposed and deveLoped~in the manner of Example l.
The resultant lithographic printing plate was washed with~water, and~ the two finishing compositions were~applied respectively to separate areas thereof. The plate was rubbed with normal lithographic inking-in ink.
The area treated with the enzyme-containing finishing composition accepted the ink immediately whereas considerable rubbing was necessary before the other area reluctantly accepted the ink.
ExamPle 5 Example 4 was repeated except that papain was the enzyme used and the composition had a pH of 6.
Similar results were obtained.
~ .
.
Example 6 Examples 4 and 5 were repeated except that phenylmercaptotetrazole was used as the oleophilising compound. Similar results were obtained.
Example 7 The folIowing finishing composition was prepared:
75 mls Trypsin/borate buffer.
5 g Triton X405 (non-ionic surfactant).
1 g Cetyltrimethylammonium brornide.
15 mls Gum Arabic.
The pH was adjusted to 8.0 with lN sodium hydroxide.
An equivaIent composition without the trypsin was also prepared and the two finishing compositions were applied to separate areas of a developed lithographic printin~g plate produced as in Example 4. Results similar to those of Example 4 were obtained.
ExamPle 8 ~ Exam? les 4 to 7 were repeated using a lithographic printing~p~late produced by the two-sheet diffusion transfer system. Similar results were again obtained.
~ The two-sheet system consisted of an electrolytically grained aluminium substrate coated with a;~silver particle/gelatin positive receiving layer and a paper~substrate coated with a silver halide/gelatin emulsion.;
Example 9 The finishing compositions of Examples 4 to 7 were appl-ied to lithographic printing plates produced by a physical development process and similar results were obtained.
The plates used consisted of an electrolytically grained aluminium substrate coated with a silver halide/gelatin emulsion. After exposure, the plates were placed in a physical developer containing a silver salt and a reducing agent.
Claims (10)
1. A finishing composition for treating a lithographic printing plate having image areas of metallic silver, the composition comprising (i) a proteolytic enzyme and (ii) a compound capable of rendering the imaye areas oleophilic.
2. A composition as claimed in claim 1 wherein the enzyme is trypsin, pepsin, ficin, papain or a bactericidal proteinase.
3. A composition as claimed in claim 1 wherein said compound is a mercapto compound.
4. A composition as claimed in claim 3 wherein said compound is 2-mercaptobenzthiazole or phenylmercaptotet-razole.
5. A composition as claimed in claim 1 wherein said compound is a cationic surfactant.
6. A composition as claimed in claim 5 wherein said compound is cetyltrimethyl ammonium bromide or cetylpyridinium chloride.
7. A composition as claimed in claim 1 and additionally including a lithographic desensitising compound.
8. A composition as claimed in claim 7, wherein said lithographic desensitising compound is gum arabic or dextrin.
9. A method of treating a lithographic printing plate having image areas of metallic silver, the method comprising applying a proteolytic enzyme and subsequently or simultaneously applying a compound capable of rendering the image areas oleophilic.
10. A method according to claim 9, comprising simultaneously or subsequently applying a lithographic desensitising compound.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB8318686 | 1983-07-11 | ||
| GB838318686A GB8318686D0 (en) | 1983-07-11 | 1983-07-11 | Lithographic printing plates |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1225951A true CA1225951A (en) | 1987-08-25 |
Family
ID=10545537
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000458513A Expired CA1225951A (en) | 1983-07-11 | 1984-07-10 | Lithographic printing plates |
Country Status (14)
| Country | Link |
|---|---|
| US (1) | US4567131A (en) |
| EP (1) | EP0131462B1 (en) |
| AT (1) | ATE67322T1 (en) |
| AU (1) | AU578617B2 (en) |
| CA (1) | CA1225951A (en) |
| DE (1) | DE3485041D1 (en) |
| DK (1) | DK163489C (en) |
| ES (1) | ES534230A0 (en) |
| FI (1) | FI80239C (en) |
| GB (1) | GB8318686D0 (en) |
| IE (1) | IE57074B1 (en) |
| NO (1) | NO173264C (en) |
| NZ (1) | NZ208859A (en) |
| ZA (1) | ZA845295B (en) |
Families Citing this family (34)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4854969A (en) * | 1986-07-02 | 1989-08-08 | Sun Chemical Corporation | Lithographic fountain solutions |
| GB8703376D0 (en) * | 1987-02-13 | 1987-03-18 | Vickers Plc | Printing plate precursors |
| GB8822746D0 (en) * | 1988-09-28 | 1988-11-02 | Kodak Ltd | Aqueous solutions of oleophilic compounds |
| DE69029944T2 (en) * | 1990-11-02 | 1997-09-04 | Agfa Gevaert Nv | Process for the production of lithographic aluminum offset printing plates |
| US5228906A (en) * | 1992-05-01 | 1993-07-20 | Fidler Kenneth L | Moistening agent for offset printing plates |
| GB9322202D0 (en) * | 1993-10-28 | 1993-12-15 | Du Pont Uk | Improvements in or relating to the recovery of silver |
| GB2290880B (en) * | 1994-06-30 | 1998-07-01 | Du Pont | Image formation |
| US5693448A (en) * | 1994-10-20 | 1997-12-02 | Agfa-Gevaert, N.V. | Method for making an offset printing plate according to the silver salt diffusion transfer process |
| CN1083777C (en) * | 1995-11-24 | 2002-05-01 | 霍西尔绘图工业有限公司 | Hydrophilized support for planographic printing plates and its preparation |
| EP0822449B1 (en) * | 1996-07-30 | 2000-04-05 | AGFA-GEVAERT naamloze vennootschap | A method for making a lithographic printing plate |
| DE19733725B4 (en) * | 1996-08-07 | 2006-11-16 | Mitsubishi Paper Mills Limited | Process for the preparation of a lithographic printing plate |
| US5853950A (en) * | 1996-10-03 | 1998-12-29 | Mitsubishi Paper Mills Limited | Process for making lithographic printing plate |
| GB9624224D0 (en) | 1996-11-21 | 1997-01-08 | Horsell Graphic Ind Ltd | Planographic printing |
| EP0848295B1 (en) * | 1996-12-10 | 2004-03-10 | Agfa-Gevaert | A method for making an offset printing plate according to the silver salt diffusion transfer process |
| US5905015A (en) * | 1996-12-10 | 1999-05-18 | Agfa-Gevaert, N.V. | Method for making an offset printing plate according to the silver salt diffusion transfer process |
| GB9702568D0 (en) * | 1997-02-07 | 1997-03-26 | Horsell Graphic Ind Ltd | Planographic printing |
| GB9710552D0 (en) | 1997-05-23 | 1997-07-16 | Horsell Graphic Ind Ltd | Planographic printing |
| US6357351B1 (en) | 1997-05-23 | 2002-03-19 | Kodak Polychrome Graphics Llc | Substrate for planographic printing |
| GB9711385D0 (en) * | 1997-06-03 | 1997-07-30 | Du Pont Uk | Heat sensitive printing plate precursors |
| GB9711382D0 (en) | 1997-06-03 | 1997-07-30 | Du Pont Uk | Heat sensitive printing plate precursors |
| GB9711387D0 (en) * | 1997-06-03 | 1997-07-30 | Du Pont Uk | Heat sensitive printing plate precursors |
| GB9711388D0 (en) * | 1997-06-03 | 1997-07-30 | Du Pont Uk | Heat sensitive printing plate precursors |
| GB9711392D0 (en) * | 1997-06-03 | 1997-07-30 | Du Pont Uk | Heat sensitive printing plate precursors |
| GB9711381D0 (en) * | 1997-06-03 | 1997-07-30 | Du Pont Uk | Heat sensitive printing plate precursors |
| GB9723026D0 (en) * | 1997-11-01 | 1998-01-07 | Du Pont Uk | Improvements in or relating to the processing of lithographic printing plate precursors |
| GB9723025D0 (en) * | 1997-11-01 | 1998-01-07 | Du Pont Uk | Improvements in or relating to the processing of lithographic printing plate precursors |
| GB2331487A (en) * | 1997-11-01 | 1999-05-26 | Agfa Gevaert Nv | Wash liquor for printing plates |
| GB2331486A (en) * | 1997-11-01 | 1999-05-26 | Agfa Gevaert Nv | Wash liquor for printing plates |
| DE19853216B4 (en) * | 1997-11-25 | 2007-08-02 | Mitsubishi Paper Mills Limited | Process for producing a lithographic printing plate and treating solution to be used therein |
| JPH11338166A (en) | 1998-03-25 | 1999-12-10 | Mitsubishi Paper Mills Ltd | Developing method of lithographic printing plate |
| US6293197B1 (en) | 1999-08-17 | 2001-09-25 | Kodak Polychrome Graphics | Hydrophilized substrate for planographic printing |
| US6869743B1 (en) * | 1999-11-16 | 2005-03-22 | Mitsubishi Paper Mills Limited | Method of processing light-sensitive material |
| US6190843B1 (en) * | 2000-04-11 | 2001-02-20 | Eastman Kodak Company | Hydrolyzed water-resistant protective overcoat for an imaging element |
| US6280912B1 (en) * | 2000-09-19 | 2001-08-28 | Eastman Kodak Company | Protective overcoat for an imaging element comprising an enzyme-treated biopolymer |
Family Cites Families (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2870704A (en) * | 1957-10-08 | 1959-01-27 | Technicolor Corp | Reduction of dye absorption in hardened gelatin relief matrices |
| US3099209A (en) * | 1960-02-26 | 1963-07-30 | Eastman Kodak Co | Process of treating residual positive silver halide images with organic sulfur to render said images oleophilic |
| NL276634A (en) * | 1961-03-30 | |||
| FR1476797A (en) * | 1966-03-02 | 1967-04-14 | Kodak Pathe | Method for transferring layers of colloid which can be used in particular in photography |
| US3830649A (en) * | 1968-07-15 | 1974-08-20 | Itek Corp | Metal photographic plate comprising a silver halide and process |
| US3620737A (en) * | 1968-08-09 | 1971-11-16 | Eastman Kodak Co | Etching of differentially hardened plates by enzymes |
| US3532599A (en) * | 1968-10-23 | 1970-10-06 | Isadore Nathan Cooperman | Process for cleaning with enzymes |
| BE788616A (en) * | 1971-09-10 | 1973-03-08 | Eastman Kodak Co | LITHOGRAPHIC PROCESSING SOLUTION |
| JPS539603A (en) * | 1976-07-15 | 1978-01-28 | Mitsubishi Paper Mills Ltd | Lithographic press plate |
| US4285276A (en) * | 1978-11-15 | 1981-08-25 | Howard A. Fromson | Method for printing employing lithographic fountain dampening solution |
| JPS5625739A (en) * | 1979-08-07 | 1981-03-12 | Fuji Photo Film Co Ltd | Preparation of printing plate |
-
1983
- 1983-07-11 GB GB838318686A patent/GB8318686D0/en active Pending
-
1984
- 1984-07-09 FI FI842741A patent/FI80239C/en not_active IP Right Cessation
- 1984-07-09 AT AT84304667T patent/ATE67322T1/en not_active IP Right Cessation
- 1984-07-09 EP EP84304667A patent/EP0131462B1/en not_active Expired - Lifetime
- 1984-07-09 AU AU30419/84A patent/AU578617B2/en not_active Ceased
- 1984-07-09 DE DE8484304667T patent/DE3485041D1/en not_active Expired - Lifetime
- 1984-07-10 NO NO842807A patent/NO173264C/en unknown
- 1984-07-10 NZ NZ208859A patent/NZ208859A/en unknown
- 1984-07-10 ZA ZA845295A patent/ZA845295B/en unknown
- 1984-07-10 CA CA000458513A patent/CA1225951A/en not_active Expired
- 1984-07-11 ES ES534230A patent/ES534230A0/en active Granted
- 1984-07-11 US US06/629,878 patent/US4567131A/en not_active Expired - Lifetime
- 1984-07-11 IE IE1784/84A patent/IE57074B1/en not_active IP Right Cessation
- 1984-07-11 DK DK341184A patent/DK163489C/en active
Also Published As
| Publication number | Publication date |
|---|---|
| AU3041984A (en) | 1985-01-17 |
| FI80239B (en) | 1990-01-31 |
| DK341184A (en) | 1985-01-12 |
| DK341184D0 (en) | 1984-07-11 |
| EP0131462B1 (en) | 1991-09-11 |
| GB8318686D0 (en) | 1983-08-10 |
| NO173264C (en) | 1993-11-24 |
| NO173264B (en) | 1993-08-16 |
| IE57074B1 (en) | 1992-04-22 |
| ATE67322T1 (en) | 1991-09-15 |
| DK163489C (en) | 1992-08-03 |
| IE841784L (en) | 1985-01-11 |
| ZA845295B (en) | 1985-03-27 |
| ES8602489A1 (en) | 1985-12-01 |
| DE3485041D1 (en) | 1991-10-17 |
| AU578617B2 (en) | 1988-11-03 |
| ES534230A0 (en) | 1985-12-01 |
| FI842741A0 (en) | 1984-07-09 |
| US4567131A (en) | 1986-01-28 |
| EP0131462A2 (en) | 1985-01-16 |
| NO842807L (en) | 1985-01-14 |
| FI80239C (en) | 1990-05-10 |
| NZ208859A (en) | 1986-08-08 |
| EP0131462A3 (en) | 1986-09-17 |
| DK163489B (en) | 1992-03-09 |
| FI842741A (en) | 1985-01-12 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA1225951A (en) | Lithographic printing plates | |
| EP0009031B1 (en) | Desensitizing solution and process for treating a diazo photosensitive printing plate | |
| US4361639A (en) | Method for treating lithographic printing plates | |
| EP0278766A2 (en) | Improvements in or relating to printing plate precursors | |
| US4220702A (en) | Method for making a lithographic printing plate | |
| JPS6123547B2 (en) | ||
| US5445914A (en) | Method for making a lithographic offset plate by the silver salt diffusion transfer process | |
| US6093522A (en) | Processing of lithographic printing plate precursors | |
| JPH0348039B2 (en) | ||
| US6063554A (en) | Processing of lithographic printing plate precursors | |
| CA2134585A1 (en) | Recovery of silver | |
| US5587271A (en) | Dampening solution for printing with a lithographic printing plate and a method for printing therewith | |
| US3091531A (en) | Hardening gelatin-silver halide lithographic offset printing plates | |
| US3429703A (en) | Photolithographic printing plates and process for producing same | |
| EP0304662A1 (en) | Damping solution for lithographic printing plate and method using it | |
| JPS58127928A (en) | Treatment of lithographic plate | |
| GB2331487A (en) | Wash liquor for printing plates | |
| JP3518719B2 (en) | Finishing liquid for lithographic printing plate and plate making method | |
| JPH0126052B2 (en) | ||
| GB2331486A (en) | Wash liquor for printing plates | |
| JPH11119442A (en) | Finishing liquid for planographic printing plate and plate making method | |
| JP2000206697A (en) | Photomechanical process for planographic printing plate | |
| EP0610983A2 (en) | A method for making a lithographic offset plate by the silver salt diffusion transfer process | |
| JPH08262723A (en) | Solution for surface treating for planographic printing plate | |
| JP2002006505A (en) | Plate-making method for planographic printing plate |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |